Question

Question 5 of 15 > -12 Plastic microparticles are contaminating the world's shorelines, and much of this pollution appears to come from fibers from washing polyester clothes. The worst offender appears to be fleece, and a recent study found that the mean number of polyester fibers discharged into wastewater from washing fleece was 290 fibers per liter of wastewater, with a standard deviation of 87.6 and a sample size of 120 1Browne, M., et. al., "Accumulation of Microplasticon Shorelines Worldwide: Sources and Sinks." Environmental Science and Technology, 2011; 45: 9175-9179. Data are approximated from information given. (a) Find a 90% confidence interval for the mean number of polyester microfibers per liter of wastewater when washing fleece. Round your answers to one decimal place. The 90% confidence interval is ta e Textbook and Media Hint Question Part Score --/0.66 (b) What is the margin of error? Round your answer to one decimal place. margin of errori e Textbook and Media Hint P

part c: also if we want a margin of error of only + - 4 with a 90% confidence ,what sample size is needed? round off to nearest integer.

Answer 1

O ZAME = 2112 solution :- aj go / confidence interval X + Zala 2 B 290 + 1.645 X 87.6 V120 276.8 303.2 zalo by Margim of erroos 1.645 X 87.6 Vizo - 13.2 I lote test S port e ) FO 4 1.645 x 87.6 ñ n 1297.8 1298 sample size =